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MSpace is the University of Manitoba’s Institutional Repository. The purpose of MSpace is to acquire, preserve and provide access to the scholarly works of University faculty and students within an open access environment.

 

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Open Access
Empowering pediatric sibling hematopoietic stem cell donor voices through digital storytelling
(2025-06-20) Winther Klippenstein, Andrea Diane; Mignone, Javier (Community Health Sciences); Scott, Shannon (Nursing); Carter, Bernie (Edgehill University); West, Christina
This participatory, arts-based qualitative study aimed to elucidate the sibling donor experience in pediatric hematopoietic stem cell transplant (HSCT). Six sibling donors aged 12-21 years of age who were under 18 at time of donation, participated as research partners and used digital storytelling (DS) to express their donation experiences. The United Nations Convention on the Rights of the Child (UNCRC) was employed as a framework to ensure that research partners' voices were heard. Research partners were actively involved in three research meetings (get to know you, digital storytelling workshop, data analysis), collaborating and contributing to the meeting dynamics while offering feedback on the participatory process and the creation of digital stories. During meeting three (data analysis), research partners viewed each other's digital stories and wrote words, thoughts, and ideas on Post-it notes to reflect their interpretations of the sibling donor experience. The primary researcher (AWK) conducted participatory data analysis with sibling donor research partners and six themes were identified and explored: 1) pessimism and acceptance, 2) after-procedure thoughts, 3) sibling support, 4) family experience, 5) connections, and 6) hope. Throughout the process, AWK and a secondary researcher (CHW, doctoral advisor) wrote field notes to capture the research process of using the digital storytelling method to empower pediatric sibling donors to express donation stories. Interpretive description was employed to analyze field notes and research partner meeting transcripts, leading to the identification of four themes: 1) community and connection; 2) digital storytelling - new and fresh; 3) therapeutic process; and 4) privacy. Digital storytelling is an arts-based approach that can assist sibling donors to express their donation experiences and offer support for growth and strength in the context of sibling donation and encourage children’s meaningful engagement and participation in research by exploring their HSCT donation experiences.
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Open Access
Unraveling the Peri-Implant Epithelial Barrier
(2025-06-18) Grauer, Joseph; Helms, Jill (Stanford University, Surgery); Stavropoulou, Chrysi (Periodontics); Kelekis-Cholakis, Anastasia (Dentistry); Bhullar, Raj (Oral Biology); Helms, Jill; Stavropoulou, Chrysi
The long-term success of dental implants relies on the formation of a protective soft tissue barrier that limits pathogen infiltration into peri-implant tissues. However, our understanding of how this barrier develops under different implant placement protocols (i.e., immediate vs. delayed placement) and in response to varying implant surface characteristics remains limited. This study systematically evaluates the formation and maturation of peri-implant soft tissues in two contexts: (1) immediate versus delayed implant placement and (2) anodized versus machined implant surfaces. Part I: Miniaturized titanium implants were placed in either fresh extraction sockets or healed maxillary first molar sites in mice. Peri-implant soft tissues were assessed at multiple time points to investigate molecular attachment mechanisms and the barrier function of the soft tissue. A healthy junctional epithelium served as a positive control. Notably, no significant differences were observed in the rate of soft tissue integration between immediate and delayed implants. However, mucosal integration took at least twice as long as osseointegration in this model. Part II: Scanning electron microscopy and surface chemistry characterization were performed on miniaturized anodized and machined implants. Following placement in fresh extraction sockets, peri-implant tissues were examined at four time points. The findings corroborated those from Part I and led to several key conclusions: 1. Maturation of the peri-implant epithelium (PIE) is a prolonged process, aligning with clinical observations. 2. Soft tissue integration occurs more slowly than bone integration. 3. Anodized implant surfaces offer a transient advantage in promoting soft tissue maturation. Together, these findings highlight the extended timeline required for PIE maturation, underscoring the potential clinical benefits of strategies aimed at accelerating this process.
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Open Access
Bitter taste genetics and association with oral health and COVID-19 outcomes in the Canadian Longitudinal Study on Aging
(2025-06-11) Shafizadeh, Marziyeh; Hitchon, Carol (Internal Medicine); Drögemöller, Britt (Biochemistry and Medical Genetics); Bhullar, Rajinder; Chelikani, Prashen
Bitter taste receptors (T2Rs, encoded by TAS2R genes) are expressed in various tissues, including the mucosal and bronchial epithelium and immune cells, where they play a crucial role in the early response to pathogens. Research on single nucleotide polymorphisms (SNPs) in TAS2Rs has focused on TAS2R38, while other TAS2R genes and pseudogenes remain largely unexplored. This thesis investigated SNPs in 25 TAS2R genes and 12 TAS2R pseudogenes in individuals of European ancestry within the Canadian Longitudinal Study on Aging (CLSA). The first part of the thesis compared the allele distribution of TAS2R SNPs with those reported in the 1000 Genomes Project (1KGP) database and examined the association between TAS2R SNPs and self-reported oral health outcomes in the CLSA cohort. The second part assessed the relationship between TAS2R SNPs and COVID-19 infection and antibody seroconversion in individuals with and without at-risk chronic medical conditions, including diabetes, immune-mediated inflammatory disease (IMID), respiratory disease, and cardiovascular disease. The analyses identified fifteen SNPs in TAS2R8, 9, 13, 14, 20, and 50 as significantly associated with self-reported sore jaw muscles, a symptom commonly linked to temporomandibular disorders (TMDs). TAS2R20 exhibited the highest number of associated SNPs. Structure-function analysis suggested that variants in TAS2R20 may contribute to this symptom by altering ligand interactions. Additionally, in the COVID-19 Questionnaire Study (N = 14,073), rs117458236 (C) in TAS2R20 (OR = 1.95, P = 0.039) was significantly associated with COVID-19 infection. In the COVID-19 Antibody Study (N = 8,313), three SNPs were associated with seroconversion: rs2234235 (G) in TAS2R1 with anti-nucleocapsid (OR = 1.55, P = 0.018) and anti-spike (OR = 0.74, P = 0.033); rs2234010 (A) in TAS2R5 with anti-nucleocapsid (OR = 1.56, P = 0.014); and rs34039200 (A) in TAS2R62P with anti-spike (OR = 0.86, P = 0.013). Subgroup analyses suggested an association between rs2234235 (G) in TAS2R1 and lower odds of spike antibody response, as well as increased risk of SARS-CoV-2 infection among individuals with IMID or respiratory disease. These findings highlight the potential of TAS2R genetic screening to identify individuals at elevated risk for TMD and COVID-19, suggesting applications in personalized medicine and vaccination strategies for high-risk groups.
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Open Access
Identification and characterization of novel antivirals for seasonal influenza A virus
(2025-06-08) Willman, Marnie; Coombs, Kevin (Medical Microbiology and Infectious Diseases); Arsenio, Janilyn (Internal Medicine); Rasmussen, Angela (University of Saskatchewan); Kobasa, Darwyn
Seasonal influenza viruses cause approximately 3-5 million cases of illness and 250,000-500,000 deaths globally annually, burdening the healthcare system. Currently, the best intervention against seasonal influenza is the annual vaccine, which protects against Influenza Type A subtypes H1N1, H3N2, and Type B viruses, all of which are endemic in humans. However, vaccine strains must be decided one year before the season, as the dominant seasonal strains may change year to year, which can lead to reduced efficacy. Typically, the first line of post-exposure defense for severe or complicated influenza infection is antivirals such as Oseltamivir. However, influenza quickly gains resistance against antivirals, limiting their value for sustained use during outbreaks. By utilizing DiscoveryProbe pre-aliquoted drug panels from ApexBio against a seasonal strain of H1N1 influenza, I aimed to discover novel antivirals to identify more options for emergency antiviral use in the case of future severe cases or seasonal IAV infection. In vitro screening of FDA-approved drug panel from ApexBio identified two compounds that provided protection against A/Canada/RV733/2007 H1N1 with limited cytotoxicity in MDCK and A549 cells. Screening of the Natural Product library panel from ApexBio identified 12 compounds that provided protection with limited cytotoxicity. Testing these compounds against seasonal and pandemic H1N1, A/Hong Kong/1/68 H3N2, a recombinant VSV, and a seasonal Rhinovirus showed that several of the compounds were effective against a wide range of infectious agents. Testing in both MDCK and A549 cell lines showed that the effectiveness of the compounds occasionally differed between cell lines. Further characterization using immunofluorescent assays to track viral proteins during infection in the presence of the compounds of interest showed that sodium aescinate, calycosin-7-glucoside, oridonin, dioscin, and kinetin reduced viral protein fluorescence 24 hours post-infection. Hemagglutination inhibition assays, attachment and penetration blockades, and attachment immunofluorescent assays suggested that oridonin and dioscin may be inhibiting on IAV attachment, while sodium aescinate and calycosin-7-glucoside may be having a negative effect on IAV penetration. These novel antivirals could provide new possibilities for treatment of influenza infections, and provide additional options for the management of inevitable future IAV outbreaks.
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Embargo
Yellow field pea and hemp protein hydrolysates as tools to enhance the health benefits and sensory quality of meat alternatives
(2025-06-04) Agunbiade, Helen; Malalgoda, Maneka (Food and Human Nutritional Sciences); Bandara, Nandika (Food and Human Nutritional Sciences); Aluko, Rotimi; Koksel, Filiz
Protein hydrolysates are known to exert positive impact on human health and are useful in managing negative health conditions. This study produced enzymatic protein hydrolysates from hemp and pea, using papain and chymotrypsin, followed by incorporation into soybean-based meat analogues (MAs). The hydrolysates, hemp papain (HP), hemp chymotrypsin (HC), pea papain (PP) and pea chymotrypsin (PC) were used at the ratio of 8, 16 and 24% (w/w) of the soy protein concentrate (SPC) to develop MAs. The extruded MAs were tested for antioxidant, textural, bitterness intensity and in vitro bioactive properties. All the MAs had DPPH and metal chelating (MC) activities higher than their individual hydrolysates. The MC activities of the MAs were reduced with increasing hydrolysate content. SPC+8%HC and SPC+8%PP had the highest MC activity (42.99%) and were not significantly different from each other. However, all the hydrolysates had higher superoxide activities than their MAs, with the PP having the highest activity (35.43%) while SPC+16%HP had the highest hydroxyl radical scavenging activity (52.64 %). There were no significant differences in the α-amylase and α-glucosidase activities of the pea hydrolysates and their respective MAs, but the hemp hydrolysates had higher activities than their MAs. The hydrolysates had lower ACE inhibitory activities when compared to their MAs with SPC+8%HP having the highest inhibition (84.14%). The MAs had decreased hardness as the hydrolysates content increased while bitterness intensity was greater for the hydrolysates. The MAs that contained protein hydrolysates showed different variabilities in their cutting forces in both longitudinal and transverse directions, however, they all exhibited good cutting forces relative to the MA that contained only SPC. All the MAs had higher acetylcholinesterase (AChE) inhibitory activity than galantamine (AChE inhibitor drug), however, those made with pea protein hydrolysates showed better inhibition than the MAs that contained hemp hydrolysates. Results from this study indicate the potential use of plant-based protein hydrolysates to enhance the sensory and health-promoting properties of MAs.
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Open Access
An ecohealth perspective of non-communicable diseases in Bangladesh: a population-based study of risk factors
(2025-06-09) Badat, Sobiya Aziz; Burke, Stacie (Anthropology); Ahsan, Gias Uddin (Natural Resources Institute); Haque, C. Emdad; Hossain, Shakhawat
The present study focused on food habits, lifestyle, residential location or place (from an ecosystem perspective) and their roles in human health, particularly in influencing non-communicable diseases in Bangladesh. Specifically, it investigated the patterns in hypertension and diabetes prevalence and their risk factors, from an Ecohealth (i.e., interdisciplinary) perspective. The three specific objectives of this study were to: (i) determine the prevalence of hypertension and diabetes among adult population in Bangladesh; (ii) examine the distribution of hypertension and diabetes by age, gender, socioeconomic status, and place of residence; and (iii) identify and analyze the relationship between hypertension as well as diabetes and their risk factors in the country. Secondary data, collected by an IDRC-sponsored project from participants residing in eight districts across Bangladesh, in various spectrums of urbanicity, including metropolitan areas, peri-urban areas (contiguous to the cities), semi-urban areas, and rural areas, were used. Both descriptive and inferential statistical techniques, applying a quantitative approach, were followed to analyze the data. The results revealed that individuals from higher SES groups exhibited healthier dietary habits, such as consuming more fruits and vegetables. Age, Body Mass Index (BMI), tobacco consumption and fruit and vegetable intake significantly influenced the likelihood of hypertension, highlighting the need for targeted interventions and preventative measures. The findings indicated that 10.7% of the population aged 18 years and above had diabetes, and that aging was a significant determinant of diabetes among Bangladeshi adults. A greater proportion of the participants with diabetes were overweight and/or obese. Among other factors, a higher level of education, likely to be associated with sedentary-oriented occupation and lifestyle, was found to be a significant risk factor for increased odds of diabetes. In addition, an ascending gradient of diabetes from rural to Upazila headquarters (semi-urban) to peri-urban and urban areas was seen. It is recommended that health policies in the country should establish standards and protocols for NCD services at all levels of healthcare. A consideration of the importance of NCD-related public education campaign regarding the ill-effects of urbanism is needed in national policy formulation -- which would help to attain Bangladesh’s commitment to the 2030 UN Sustainable Development Goals.
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Open Access
Direct numerical simulation of turbulent flow and heat transfer in a square duct roughened by longitudinal ribs
(2025-06-15) Tachie, Mark Sedem; Ormiston, Scott (Mechanical Engineering); Essel, Ebenezer (Mechanical Engineering); Wang, Bing-Chen
This thesis provides a detailed study of turbulent heat and fluid flow within a longitudinally-rib-roughened square duct using direct numerical simulations (DNS). To understand the rib effects on the velocity and temperature fields, DNS of turbulent convection in a smooth-wall duct is also performed which serves as a baseline case of comparison. The research consists of three major parts. In Part I, turbulent flow through a longitudinally-rib-roughened square duct is studied at a nominal bulk Reynolds number of $Re^{N}_{b}=4410$. It is observed that the mean pattern of the secondary flows is sensitive to the presence of the ribs, and tertiary flows form at the roofs and roots of the ribs, leading to enhanced momentum transport throughout the cross-stream plane. The effects of ribs on the velocity field are further studied through analyses of the Reynolds stresses, budget balance of turbulence kinetic energy (TKE), and skewness and flatness factors of velocity fluctuations. In Part II, the influence of ribs on the statistical moments of the vorticity and velocity fields are demonstrated through analyses of the transport equation of the mean streamwise vorticity, enstrophy, as well as the joint probability density function (JPDF) of velocity fluctuations. Through a spectral analysis, it is found that the characteristic wavelength of the most energetic turbulent eddies is shortened in the ribbed duct. In Part III, turbulent heat transfer in three longitudinally-ribbed duct flows at nominal bulk Reynolds numbers of $Re^{N}_{b}=2730$, 4410 and 9650 are studied. It is observed that the presence of longitudinal ribs strengthens the secondary flows, which become intensified as Reynolds number increases, leading to enhanced thermal energy transport. It is also observed that the presence of longitudinal ribs does not result in increased hydraulic losses. As the value of Reynolds number increases, the heat transfer coefficient increases monotonically. The effects of longitudinal ribs and Reynolds number on turbulent heat transfer in a square duct are further examined by analyzing the turbulent heat fluxes, budget balance of the temperature variance transport equation, and thermal structures in both the physical and spectral spaces.
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Open Access
Computed tomography perfusion assessment of poor neurological outcome in comatose cardiac arrest patients (CANCCAP): a prospective study
(BMC, 2025-05-23) Shankar, Jai; Alcock, Susan; Wiens, Evan; Ayroso, Marco; Park, JaeYeon; Singh, Navjit; Blackwood, Benjamin ; Trivedi, Reva; Marin, Roman; Sinha, Namita; Trivedi, Anurag; Kirkpatrick, Iain; Essig, Marco; Schaffer, Stephen
Abstract Background Computed tomography perfusion (CTP) of the brain, are increasingly being employed for the assessment of critically ill patients admitted to intensive care units (ICU), including comatose cardiac arrest patients (CCAP). The purpose of our study was to validate the use of CTP in predicting in-hospital mortality in CCAPs. Method This prospective cohort study enrolled newly admitted adult CCAP, with an out of hospital cardiac arrest (OHCA) and were scheduled for admission to the ICU for further management. Just before ICU admission, CCAP underwent a routine CT scan of the head and CTP of whole head. The treating physicians remained blinded to the CTP results and all patients received standard management. The CTP maps were evaluated to determine a binary outcome of non-survivable brain injury (NSBI), by two independent neuroradiologists, blinded to each other’s assessment and to the clinical history of the patients. Results A total of 91 patients were enrolled and 90 (Male-78; mean age-62 years) were included in the final analysis. One patient declined consent. Of these, 42 individuals (47%) had in-hospital mortality. Patients with in-hospital mortality were older; had higher levels of creatinine, blood urea nitrogen, blood CO2 and lower pH, carbonate, and heart rate. In multivariate analysis, PCI was independently associated with reduction in-hospital mortality. CTP demonstrated exceptionally high specificity (100%; 95% CI 92–100%) and positive predictive value (100%; 95%CI 6.3–100%) for the prediction of NSBI. For CTP, Bennet’s S-score showed excellent agreement between the two readers (s = 0.82–0.95). Conclusion CTP was safe and demonstrated very high specificity and positive predictive value and may be used as an additional diagnostic tool for identifying patients at high risk of in-hospital mortality.
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Open Access
Erroneous calibration of esophageal pressure in case of airway closure
(BMC, 2025-05-02) Docci, Mattia; Beloncle, Francois; Lesimple, Arnaud; Piraino, Thomas; Raimondi Cominesi, Davide; Restivo, Andrea; Sousa, Mayson L. A.; Rezoagli, Emanuele; Mercat, Alain; Richard, Jean-Christophe; Brochard, Laurent
Abstract Airway closure results in a lack of communication between proximal and distal airways unless the airway pressure (Paw) overcomes the airway opening pressure (AOP). This has been described in patients undergoing mechanical ventilation with acute respiratory distress syndrome, obesity, hydrostatic pulmonary edema and during cardiopulmonary resuscitation. In these categories of patients, esophageal pressure (Pes) can guide the personalization of mechanical ventilation and calibration of the esophageal balloon is necessary to obtain reliable Pes measurements. The impact of airway closure has never been envisaged. This study investigated the impact of airway closure on the calibration of the esophageal balloon by the ∆Paw/∆Pes following a positive pressure occlusion test during passive mechanical ventilation. The calibration test was performed in twelve human cadavers with airway closure at end-expiration at different levels of positive end-expiratory pressure (PEEP) and at end-inspiration. The ∆Paw/∆Pes measured at end-expiration and at end-inspiration were significantly different when total PEEP was lower than AOP (estimated means 0.42 [0.40; 0.44] vs. 0.95 [0.92; 0.97], P < 0.001), while this difference was not observed when total PEEP was higher than AOP (estimated means 0.99 [0.92; 1.05] vs. 0.99 [0.92; 1.06], P = 0.854). These results were corroborated by observations during esophageal balloon calibration in two patients requiring Pes monitoring for clinical management. In case of airway closure, compression of the chest is not fully transmitted to the airways. This can lead to a conspicuous underestimation of the ∆Paw/∆Pes and poor reliability of this monitoring technique when the test takes place below AOP. Our results favor a positive pressure occlusion test performed during an end-inspiratory occlusion as the new standard of operative procedures for positioning and calibrating the esophageal balloon.
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Open Access
Genome mining of Leptographium wingfieldii, an invasive species in Canadian forests, and related taxa in the order Ophiostomatales for the characterization of secondary metabolites and ribozymes
(2025-05-06) Zubaer, Abdullah; Court, Deborah (Microbiology); Domaratzki, Mike (Computer Science); Smith, David R. (Western University); Hausner, Georg; Tremblay-Savard, Olivier
Leptographium wingfieldii is an invasive fungal species in Canadian forests which was originally isolated in Europe (France and Greece). Leptographium wingfieldii and other fungi in the order Ophiostomatales (Ascomycota) are vectored by arthropods, and they can be either pathogenic to tree species or cause blue stain on sapwood in conifer (and hardwood) species. These fungi are ecologically and economically significant due to their impact on forest ecosystems and lumber industry. Whole genome sequences were obtained from Leptographium wingfieldii and related fungi (including Leptographium procerum, Leptographium terebrantis, Grosmannia aureum, Ophiostoma minus, and Ophiostoma piliferum). The mitochondrial genomes of these fungi were assembled and found to contain autocatalytic group I and group II introns, intron-encoded homing endonucleases along with intron-encoded reverse transcriptase enzymes that have applications in genome editing. These elements contribute toward the genetic diversity observed among the mitochondrial genomes studied. The study provided information to generate a mitochondrial intron landscape, identified complex intron arrangements, and demonstrated the correlation of mitogenome expansion with the number of introns. The whole genome sequence data were also analyzed with regards to the presence of nuclear genome encoded biosynthetic gene clusters (BGCs). This effort identified the presence of 205 BGCs categorized into PKS I, PKS III, NRPS, RiPPS, Terpenes, and hybrid types and these could be sources for potential antimicrobials and industrially important chemical compounds. The study provides a platform for downstream biochemical characterization and heterologous expression of the identified genetic elements, facilitating their functional annotation and explore their potential for industrial applications.